import static org.junit.Assert.*;
import org.junit.Test;

public class Main {
    @Test
    public void testAddition() {
        ExpressionFactory factory = new ExpressionFactory();
        Expression addition = factory.createExpression("addition", 5, 3);
        assertEquals(8, addition.evaluate());
    }

    @Test
    public void testSubtraction() {
        ExpressionFactory factory = new ExpressionFactory();
        Expression subtraction = factory.createExpression("subtraction", 5, 3);
        assertEquals(2, subtraction.evaluate());
    }
}